Extracellular matrix based gastroesophageal junction reinforcement device

ABSTRACT

Provided are medical devices for implantation in patients having suffered the loss of or damage to at least part of their esophagus. The medical device connects the esophagus or remaining part thereof with the stomach to form a gastro-esophageal junction that promotes healing and encourages new host tissue growth while distributing the load and decreasing tension at the anastomotic site. The medical device comprises extracellular matrix shaped into a conformation that more closely approximates the geometry of the native gastro-esophageal junction than does direct attachment of the stomach to the shortened esophagus. Molds useful in manufacturing the medical device and methods of use of the device are also described herein.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/650,015, filed Jan. 5, 2007, which claims the benefit of U.S.Provisional Patent Application Nos. 60/757,086, filed on Jan. 6, 2006,each of which is incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERAL FUNDING

This invention was made with government support under Grant No. 1 R43DK069110-01, awarded by the National Institutes of Health. Thegovernment has certain rights in this invention.

Described herein are medical devices for implantation in patients thatmay be used to connect an esophagus or portions thereof with a stomachto form and/or repair a gastro-esophageal junction. Methods of use ofthe medical device are also described herein.

Surgical procedures involving the esophagus have always been challengedby their high morbidity and mortality rates (Orringer and Stirling,1988, J Thorac Cardiovasc Surg. 96:887-93; Heitmiller et al., 1999, DisEsophagus. 12:264-9; Whyte and Orringer, 1994, Semin Radiat Oncol.4:146-156). Radical esophagectomy, the therapy of choice for patientswith esophageal cancer or patients with high grade dysplasia, is usuallyfollowed by a complex reconstructive surgery to restore food transit.The most commonly accepted approach has been mobilizing the stomachthrough the mediastinum after shaping it into a tube and anastomosing itto the remaining cervical esophagus (“gastric pull-up”)(Orringer et al.,2001, World J Surg. 25:196-203). When the stomach is not available,other options such as colonic or small bowel interposition are utilized(Yildirim, 2004, J Gastrointest Surg. 8:675-8). Although partiallysuccessful, the outcome of these procedures remains suboptimal due tothe high associated morbidity (Iannettoni et al., 1995, J ThoracCardiovasc Surg. 110:1493-500). The mobilization of the abdominal organsinto the mediastinal cavity usually yields to extensive compromise ofthe blood supply and the resulting poorly vascularized tissue has areduced healing capacity that contributes to complications at theanastomotic site (Reavis et al., 2005, Ann Surg. 241:736-45).Anastomotic leakage is the most common complication associated with highmorbidity and it is considered an independent risk factor in theprognostic outcome (Rizk et al., 2004, J Am Coll Surg. 198:42-50). Formany years, surgeons have attempted modifications of the surgicaltechnique to improve this condition with limited success. In fact,controversy still exists on whether a complete mechanical anastomosissignificantly decreases the leak rate when compared to a hand sewnanastomosis. Another common complication related to poor healingcapacity and scarring is the post-operative stricture of the anastomosisthat requires endoscopic dilation in up to 50% of patients (Orringer etal., 2001, World J Surg. 25:196-203). On the other hand, partialresection of the esophagus (i.e. mucosectomy in Barret's disease) islimited by the inability of the tissue to regenerate in an organizedmanner and leads to scar tissue formation and ultimately esophagealstenosis (Stein et al., 2000, Ann Surg. 232:733-42; DeMeester andDeMeester, 1999, Adv Surg. 33:29-68).

There exists a need for anastomotic reinforcement in connection withsurgical procedures involving the esophagus. Recently, regenerativemedicine approaches have shown promising results using extracellularmatrix (ECM) scaffolds derived from the small intestinal submucosa (SIS)and urinary bladder (UBM) in the attempt to reconstitute normal tissue.Several pre-clinical and clinical applications have been reported fornumerous body structures including vascular, skin, musculo-skeletal,lower urinary tract, and esophageal tissue.

SUMMARY

ECM scaffolds are provided as anastomotic reinforcement devices and toreduce scarring and inflammation to better promote healing withdecreased complications. Thus provided, according to one embodiment ofthe medical devices described herein, are medical devices forimplantation in patients having lost at least part of their esophagus orhaving damage to their esophagus. According to one embodiment, themedical devices described herein connect the esophagus or remaining partof the esophagus with the stomach to form a gastro-esophageal junctionthat promotes healing and encourages new host tissue growth, diminishesscar tissue formation and stricture while distributing the load,decreasing tension, and increasing vascular perfusion at the anastomoticsite. The medical device comprises extracellular matrix (ECM) shapedinto a conformation that more closely approximates the geometry of thenative gastro-esophageal junction than does direct attachment of theremaining stomach, often tubularized, to the shortened esophagus.Methods of use of the medical device are also encompassed by the presentinvention.

In one embodiment, a device is provided comprising one or more layers ofextracellular matrix tissue, for example and without limitation 2-10layers, and comprising a tubular esophageal portion having essentially aconstant diameter (the diameter can increase, decrease or vary so longas it substantially conforms with a shape of a portion of an esophagus);and a tubular gastric portion attached to the esophageal portion at ajunction having a diameter that increases from the junction to a distaltip of the gastric portion. The diameter of the gastric portion mayincreases in an essentially uniform manner from the junction to thedistal tip of the gastric portion. Typically, the gastric portion ismodeled to conform with a portion of a patient's stomach to which aremaining portion of the patient's esophagus is to be attached, and inone embodiment, the gastric portion is modeled to conform with a cardiacregion of a stomach adjacent to a cardiac opening of the stomach.

In certain embodiments, the esophageal portion has a length of between 1to 30 cm and a diameter of between 0.5 to 5 cm; and/or the gastricportion has a length of between 1 to 8 cm and the distal tip of thegastric portion has a diameter of between 1-12 cm. According to otherembodiments, the esophageal portion has a length of about 3 cm and adiameter of about 2.3 cm; and/or the gastric portion has a length ofabout 3-4 cm and a diameter of the distal tip of about 7 cm.

The extracellular matrix tissue may be isolated by any useful methodfrom any useful source. In one example, the tissue is isolated fromurinary bladder tissue, for example and without limitation porcineurinary bladder tissue. The extracellular matrix tissue may compriseepithelial basement membrane and subjacent tunica propria. Theextracellular matrix tissue may comprise tunica submucosa. Theextracellular matrix tissue may comprise epithelial basement membrane,subjacent tunica propria, tunica submucosa and/or tunic muscularis. Theextracellular matrix tissue also may be isolated from intestinalsubmucosa, esophagus or dermis of skin. The device may be seeded withcells, typically human cells, such as a patient's cells into whom thedevice is to be implanted or allogeneic cells. The cells may beimplanted in the device prior to surgery and may be allowed to populatethe device prior to surgery by incubation in a bioreactor. Alternately,autologous or allogeneic cells may be implanted at the time of surgery,for example and without limitation, by sattaching a suitable piece oftissue to the device during implantation surgery.

Also provided is a mold for molding extracellular matrix tissue into adevice as described herein, comprising a tubular esophageal portionhaving essentially a constant diameter (the diameter can increase,decrease or vary so long as it substantially conforms with a shape of aportion of an esophagus), and a tubular gastric portion attached to theesophageal portion at a junction, the gastric portion having a diameterthat increases from the junction to a distal tip of the gastric portion.As with the device described herein, the diameter of the gastric portionof the mold may increase in an essentially uniform manner from the pointof connection to the esophageal portion to the distal tip of the gastricportion. In other embodiments, the esophageal portion of the mold has alength of between 1 to 30 cm and a diameter of between 0.5 to 5 cm; andthe gastric portion has a length of between 1 to 8 cm and the distal tipof the gastric portion has a diameter of between 1-12 cm. In furtherembodiments, the esophageal portion has a length of about 3 cm and adiameter of about 2.3 cm; and the gastric portion has a length of about3-4 cm and a diameter of the distal tip of about 7 cm. The mold may bemade of one or more water-permeable materials. In certain embodiments,the gastric portion is modeled to conform with a portion of a stomach,for example and without limitation, the gastric portion is modeled toconform with a cardiac region of a stomach adjacent to a cardiac openingof the stomach. Due to variations in esophageal and gastric geometryprior to and after surgery, the esophageal portion of the mold may bedetachable from the gastric portion to allow interchangeability ofdifferent-shaped gastric portions. Further, the mold may be collapsibleby any means known in the art to facilitate removal of the device fromthe mold.

In another embodiment of the technology described herein, a method isprovided of reinforcing an anastomotic site in a patient comprisingimplanting a device between a portion of (e.g., that portion remainingafter surgery) the patient's esophagus and stomach, the device can beany device comprising one or more layers of extracellular matrix tissueand comprising a tubular esophageal portion having essentially aconstant diameter; and a tubular gastric portion attached to theesophageal portion at a junction having a diameter that increases fromthe junction to a distal tip of the gastric portion and variationsthereof described herein. In certain embodiments, the patient has orpreviously has had Barrett's disease, esophageal cancer, congenitalatresia, or trauma to the esophagus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a cross-sectional view of the wall of theurinary bladder (not drawn to scale). The following structures areshown: epithelial cell layer (A), basement membrane (B), tunica propria(C), muscularis mucosa (D), tunica submucosa (E), tunica muscularisexterna (F), tunica serosa (G), tunica mucosa (H), and the lumen of thebladder (L).

FIGS. 2A-2C show schematically two embodiments of an extracellularmatrix device described herein. FIG. 2A provides two views of a firstembodiment and FIG. 2C provides a single view of a second embodiment asdescribed herein. The esophageal and gastric portions of the device areindicated as well as the proximal and distal tips of the device.

FIGS. 3A-3D schematically show implantation of one embodiment of adevice described herein in a cervical esophageal anastomosis.

FIGS. 4A-4C show implantation of one embodiment of a device describedherein in a gastro-esophageal junction anastomosis.

DETAILED DESCRIPTION

The present invention is related to a medical device to be implanted inpatients having suffered the loss of or damage to at least part of theiresophagus. The device comprises one or more layers of extracellularmatrix (ECM) molded into a particular shape that more closelyapproximates the geometry of the native gastro-esophageal junction thandoes direct attachment of the remaining stomach to the shortenedesophagus. In one embodiment, the ECM is molded into a shape thatessentially recapitulates the native geometry of the gastro-esophagealjunction (the portions of the stomach and esophagus adjacent to thecardiac orifice) prior to tissue loss. The device serves as an inductivesupport scaffold that facilitates constructive remodeling of this sitefollowing segmental esophagectomy.

As used herein, the terms “extracellular matrix” and “ECM” refer to acomplex mixture of structural and functional biomolecules including, butnot limited to, structural proteins, specialized proteins,proteoglycans, glycosaminoglycans, and growth factors that surround andsupport cells within mammalian tissues.

Any type of extracellular matrix tissue can be used to make a device asdescribed herein (see generally, U.S. Pat. Nos. 4,902,508; 4,956,178;5,281,422; 5,352,463; 5,372,821; 5,554,389; 5,573,784; 5,645,860;5,771,969; 5,753,267; 5,762,966; 5,866,414; 6,099,567; 6,485,723;6,576,265; 6,579,538; 6,696,270; 6,783,776; 6,793,939; 6,849,273;6,852,339; 6,861,074; 6,887,495; 6,890,562; 6,890,563; 6,890,564; and6,893,666). In certain embodiments, the ECM is isolated from avertebrate animal, for example and without limitation, from a warmblooded mammalian vertebrate animal including, but not limited to,human, monkey, pig, cow and sheep. The ECM can be derived from any organor tissue, including without limitation, urinary bladder, intestine,liver, esophagus and dermis. In one embodiment, the ECM is isolated froma urinary bladder. The ECM may or may not include the basement membraneportion of the ECM. In certain embodiments, the ECM includes at least aportion of the basement membrane. The material used to make the ECMDevice may comprise primarily (that is, greater than 70%, 80%, or 90%)ECM. This material may or may not retain some of the cellular elementsthat comprised the original tissue such as capillary endothelial cellsor fibrocytes.

In one embodiment, the ECM is harvested from porcine urinary bladders.Briefly, the ECM is prepared by removing the urinary bladder tissue froma pig and trimming residual external connective tissues, includingadipose tissue. All residual urine is removed by repeated washes withtap water. The tissue is delaminated by first soaking the tissue in ade-epithelializing solution such as hypertonic saline, for example andwithout limitation, 1.0 N saline, for periods of time ranging from 10minutes to 4 hours. Exposure to hypertonic saline solution effectivelyremoves the epithelial cells from the underlying basement membrane. Thetissue remaining after the initial delamination procedure includesepithelial basement membrane and the tissue layers abluminal to theepithelial basement membrane. This tissue is next subjected to furthertreatment to remove the majority of abluminal tissues but not theepithelial basement membrane. The outer serosal, adventitial, smoothmuscle tissues, tunica submucosa and most of the muscularis mucosa areremoved from the remaining de-epithelialized tissue by mechanicalabrasion or by a combination of enzymatic treatment, hydration, andabrasion. Mechanical removal of these tissues is accomplished by removalof mesenteric tissues with, for example, Adson-Brown forceps andMetzenbaum scissors and wiping away the tunica muscularis and tunicasubmucosa using a longitudinal wiping motion with a scalpel handle orother rigid object wrapped in moistened gauze. After these tissues areremoved, the resulting ECM consists mainly of epithelial basementmembrane and subjacent tunica propria (layers B and C of FIG. 1).

In another embodiment, the ECM is prepared by abrading porcine bladdertissue to remove the outer layers including both the tunica serosa andthe tunica muscularis (layers G and F in FIG. 1) using a longitudinalwiping motion with a scalpel handle and moistened gauze. Followingeversion of the tissue segment, the luminal portion of the tunica mucosa(layer H in FIG. 1) is delaminated from the underlying tissue using thesame wiping motion. Care is taken to prevent perforation of thesubmucosa (layer E of FIG. 1). After these tissues are removed, theresulting ECM consists mainly of the tunica submucosa (layer E of FIG.1).

The ECM can be sterilized, and typically decellularized by any of anumber of standard methods without loss of its ability to induceendogenous tissue growth. For example, the material can be sterilized bypropylene oxide or ethylene oxide treatment, gamma irradiation treatment(0.05 to 4 mRad), gas plasma sterilization, peracetic acidsterilization, or electron beam treatment. The material can also besterilized by treatment with glutaraldehyde, which causes cross linkingof the protein material, but this treatment substantially alters thematerial such that it is slowly resorbed or not resorbed at all andincites a different type of host remodeling which more closely resemblesscar tissue formation or encapsulation rather than constructiveremodeling. Cross-linking of the protein material can also be induced byphysical and/or chemical methods, including without limitation,treatment with carbodiimide or dehydrothermal or photooxidation methods.More typically, ECM is disinfected by immersion in 0.1% (v/v) peraceticacid (σ), 4% (v/v) ethanol, and 96% (v/v) sterile water for 2 h. The ECMmaterial is then washed twice for 15 min with PBS (pH=7.4) and twice for15 min with deionized water.

Commercially available ECM preparations can also be used to make the ECMDevice of the invention. In one embodiment, the ECM is derived fromsmall intestinal submucosa or SIS. Commercially available preparationsinclude, but are not limited to, Surgisis™, Surgisis-ES™, Stratasis™,and Stratasis-ES™ (Cook Urological Inc.; Indianapolis, Ind.) andGraftPatch™ (Organogenesis Inc.; Canton Mass.). In another embodiment,the ECM is derived from dermis. Commercially available preparationsinclude, but are not limited to Pelvicol™ (sold as Permacol™ in Europe;Bard, Covington, Ga.), Repliform™ (Microvasive; Boston, Mass.) andAlloderm™ (LifeCell; Branchburg, N.J.). In another embodiment, the ECMis derived from urinary bladder. Commercially available preparationsinclude, but are not limited to UBM (Acell Corporation; Jessup, Md.).

In further embodiments, the device may be seeded with cells, typicallyautologous or allogeneic cells, prior to or during implantation. In oneexample, the device is co-cultured ex vivo in a suitable bioreactor witha patient's (allogeneic) cells or with cells from another patient(allogeneic). Suitable cells are, for example and without limitation,smooth muscle cells, bone marrow cells, cheek scrapings and biopsiesfrom healthy esophageal or intestinal tissue from the patient or fromanother patient. Cells from a patient, such as cells obtained from abiopsy of healthy tissue obtained during surgery can be seeded onto thedevice, for example by suturing a small portion the other tissue ontothe device during surgery. Variations on these methods would be apparentto one of skill in the art.

According to one embodiment of the device described herein, the ECMdevice is molded to closely approximate the shape of a gastro-esophagealjunction, for example and without limitation, a human gastro-esophagealjunction. The mold used to process the extracellular matrix (ECM) intothe ECM Device of the invention can be made from any suitable material,such as, without limitation, a plastic and is shaped into a form thatapproximates the geometry of the native gastro-esophageal junction. Thismold structure forms an ECM device that more closely approximates theshape of a native gastro-esophageal junction than the shape of thejunction formed by direct attachment of the remaining stomach to theshortened esophagus during standard esophagectomy surgical procedures.In reference to the ECM device shown in FIGS. 2A and 2B, the ECM device10, as well as its mold are generally funnel-shaped and comprise anesophageal portion 20 of length L_(E) ending in a proximal tip 25 and agastric portion 30 of length L_(G) ending in a distal tip 35 (see FIG.2). Esophageal portion 20 and gastric portion 30 are joined at junction40. Esophageal portion 20 is tubular and has a diameter that isessentially constant. Gastric portion 30 also is tubular, but itsdiameter increases from the junction 40 to the distal tip 35 in a shapethat is roughly frustro-conical, but which has a curved profile as thegastric portion 30 radiates from the junction 40 to the distal tip 35.In use, esophageal portion 20 of the ECM device 10 is connected to thegastric (inferior) end of the remaining esophagus in a patient to betreated while the gastric portion 30 of the ECM device 10 is connectedto the stomach in the patient to be treated. FIG. 2C shows an alternateembodiment of device 110 in which the gastric portion is frustro-conicalin that this embodiment exhibits a linear profile as the gastric portionradiates from the junction to the distal tip.

The mold may comprise two detachable parts, a gastric portion and anesophageal portion. The size and shape of the esophagus of many patientsmay vary from patient-to-patient, as would the size and shape of thestomach to which the device would be implanted. Further, the surgicalprocedure requiring the device would vary, with some surgeonstubularizing the portion of the stomach to which the device is attachedto varying extents. As such, according to one embodiment, a number ofdifferent-sized and different-shaped gastric and esophageal moldportions are provided that can be independently matched in order tocustomize the ECM device. The two portions can connect by any usefulmethod.

FIGS. 3A-3D schematically show a cervical esophageal anastomosis usingone embodiment of a device described herein. FIG. 3A shows a superiorterminus of an upper esophagus 150 to be attached to an inferiorterminus of a lower portion (152 in FIGS. 3B-3D) of the same esophagus.The inner wall of superior terminus 150 is shown in phantom. Inpreparation for anastomosis, endomucosa 151 is removed from the end ofsuperior terminus 150 as shown. FIG. 3B is an exploded view of theanastomosis, showing superior terminus 150, inferior terminus 152 andECM device 154. Endomucosa is removed from inferior terminus 152 in thesame manner as with superior terminus 150 shown in FIG. 3A. FIGS. 3C and3D show completed anastomosis. FIG. 3C shows an exterior view ofsuperior terminus 150 and inferior terminus 152, sutured with sutures156 and with ECM device 154 shown in phantom. FIG. 3D shows across-sectional view of the repaired esophagus shown in FIG. 3C, showingsuperior terminus 150, inferior terminus 152, ECM device 154 and sutures156.

FIGS. 4A-4C show anastomosis of superior terminus 150 of esophagus to astomach 252 according to one embodiment of the methods described herein.FIG. 4A is an exploded view of the anastomosis, showing superiorterminus 250, stomach 252 and ECM device 254. As with FIG. 3A,endomucosa is removed from the end of superior terminus 250 and fromcardiac region 260 of the stomach 252 in preparation for anastomosis.FIGS. 4B and 4C show completed anastomosis. FIG. 4B shows an exteriorview of superior terminus 250 and stomach 252, sutured with sutures 256and with ECM device 254 shown in phantom. FIG. 4C shows across-sectional view of the repaired gastro-esophageal junction shown inFIG. 4B, showing superior terminus 250, stomach 252, ECM device 254 andsutures 256.

It will be apparent to those of skill in the art that the anastomosismethods illustrated in FIGS. 3A-3D and 4A-4C are for illustrationpurposes only and variations in this surgical procedures would beapparent to surgeons and others of skill in the art. For instance, somesurgeons would not remove the endomucosa from the esophageal and/orstomach portions. Further, the ECM device might be placed external to(on the outside of) the stomach and esophagus. In that case, the stomachand remaining esophagus is attached and then the device is sewn on theoutside of the newly-formed gastro-esophageal junction. During thesurgical procedure, the device may be trimmed or modified as a surgeonsees fit in order to further customize the device.

A kit also may be provided that includes suitable, typically sterilepackaging and the device according to any embodiment described herein.Suitable packaging materials and configurations are known in the art.For example and without limitation, any device described herein can bedistributed in a blister pack comprising a plastic container with afoil, plastic and/or paper tear-away cover. This kit would be suitablefor shipping or other distribution from a manufacturing facility to anend-user or distribution point in the relevant market.

As used herein, the terms “essentially,” “substantially,” and “about”refer to slight variations in structure or function that approximate astated value and slight variations in tolerances are acceptable in theusefulness of a device, apparatus or method. For example, in the contextof a device described herein, the diameter of the esophageal portion maybe described as “essentially constant” meaning that slight variations indiameter are tolerable, so long as the device can function in thedesired context, that is, for example and without limitation, forreinforcement of esophageal or gastro-esophageal anastomosis.

The actual dimensions of the mold to be used will be largely dictated bythe needs of a patient to be treated. The dimensions will vary dependingon the native esophageal and stomach tissue and the particulardiameter/morphology of the remaining stomach and/or esophagus. Theesophageal portion of the mold typically has a length of between 1 to 30cm. The gastric portion of the mold has a length of between 1 to 8 cm.In some embodiments, the esophageal portion and the gastric portion ofthe mold are approximately equal in length. In other embodiments, theesophageal portion and the gastric portion of the mold are unequal inlength. In a specific embodiment, the esophageal portion of the mold islonger in length than the gastric portion of the mold. In anotherspecific embodiment, the gastric portion of the mold is longer in lengththan the esophageal portion of the mold. The gastric portion typicallyis modeled after (molded to conform to) a portion of a patient'sstomach, typically, but not exclusively to a cardiac portion of apatient's stomach (that portion of a patient's stomach immediatelyadjacent to the cardiac opening at the gastro-esophageal junction).

The esophageal portion of the mold is generally narrower in diameterthan the gastric portion of the mold and typically has an inner diameterof between 0.5 to 5 cm.

The gastric portion of the mold does not have a constant inner diameter.Rather, the diameter increases from the point of connection to theesophageal portion to the distal tip. The increase in diameterthroughout the gastric portion can be a uniform gradient or it can be anon-uniform in gradient. In one exemplary embodiment, the diameter ofthe gastric portion increases in a (linear or non-linear) uniformgradient from the junction between the esophageal portion and thegastric portion to the distal tip. The distal tip of the gastric portionof the mold typically has an inner diameter of between 1 to 12 cm.

The gastric portion can be any shape. The shape of the gastric portionincludes, but is not limited to, conformations that result in the distaltip being circular, ellipsoid, octagonal, hexagonal, pentagonal, etc. Inone embodiment, the gastric portion is shaped such that the distal tipis circular.

In one particular embodiment, the esophageal portion of the mold has aninternal diameter of about 2.3 cm and a length of about 3 cm while thegastric portion has an internal diameter of the distal tip of about 7 cmand a length of about 3-4 cm.

The mold may be made of any material compatible with the processingdescribed above. In certain embodiments, the material iswater-permeable. As used herein, the term “water-permeable” includessurfaces that are water absorbent, microporous or macroporous.Macroporous materials include perforated plates or meshes made ofplastic, metal, ceramics or wood. Macroporous materials, such asperforated materials or screens, are useful in the drying processbecause they result in increased available device surface area and theyfacilitate the ability to create a vacuum on the inside of the mold andtherefore on an inside surface of the device, for example as describedbelow.

As used herein, the term “Extracellular Matrix Device” refers toextracellular matrix that has been applied to a mold as described hereinand processed such that it has adopted the shape of the mold (seegenerally U.S. Pat. Nos. 5,885,619; 5,955,110; 5,968,096; and6,187,039).

The mold for the ECM Device may be wrapped with a protective layer tofacilitate removal of the ECM from the mold after processing. In oneembodiment, the mold is wrapped with umbilical tape. In anotherembodiment, the mold is wrapped with cheese cloth. In one particularembodiment, the esophageal portion of the mold is wrapped in umbilicaltape and the gastric portion of the mold is wrapped in cheese cloth. Themold also may be collapsible to facilitate removal of the device. Forexample and without limitation, folding points may be incorporated intothe mold, or the mold may be splittable into two or more portions.

Any number of layers of ECM can be used to make the ECM device. In oneembodiment 2-20 layers of ECM are used. In another embodiment, 2-10layers of ECM are used. In yet another embodiment, 3-6 layers of ECM areused. In a further embodiment, 4 layers of ECM are used.

One or more hydrated sheets of ECM are formed around the mold. Where thesheets of ECM overlap (either the two ends of a single ECM sheet fullywrapped around the mold or the ends of two different sheets of ECM eachpartially wrapped around the mold), the seam formed can be sutured toform a water tight seal and/or can be fixed to one another usingstandard techniques known to those skilled in the art (for example andwithout limitation, with a crosslinking agent such as glutaraldehyde).The mold and ECM are then placed under compression conditions including,but not limited to, placement into a plastic pouch and attachment to avacuum pump (e.g., Leybold, Export, Pa., Model D4B) with a condensatetrap inline under a vacuum of 28 to 29 in Hg for 10 to 12 h.

In one embodiment the mold and ECM are compressed under dehydratingconditions. As used herein, the term “dehydrating conditions” refers toany mechanical or environmental condition which promotes or induces theremoval of water from the ECM. To promote dehydration of the compressedECM, at least one of the surfaces compressing the tissue is waterpermeable. Dehydration of the tissue can optionally be further enhancedby applying blotting material, heating the tissue or blowing air acrossthe exterior of the compressing surfaces.

After compression, the ECM Device is then removed from the mold andterminally sterilized, for example and without limitation, with ethyleneoxide.

A patient having any disorder involving the loss or absence of at leasta portion of the esophagus can be treated using the methods and devicesdescribed herein. In certain non-limiting embodiment, the patient to betreated by the methods and devices described herein has lost at least10%, 25%, 35%, 50%, 75%, 80%, or 90% of the length of their esophagus.In another embodiment, the patient to be treated by the methods anddevices described herein has lost the full circumference of at leastpart of their esophagus. In another embodiment, the patient to betreated by the methods and devices described herein has lost less thanthe full circumference of at least part of their esophagus including,but not limited to, at least 10%, 25%, 35%, 50%, 75%, 80%, or 90% of thecircumference of the esophagus. In such an embodiment, the portion ofthe circumference of the esophagus missing may or may not be contiguous.In another embodiment, the patient to be treated by the methods anddevices described herein has lost at least a portion of the lining ofthe esophagus but retains at least some autologous muscle tissue and/orsubmucosal layer of the esophagus.

In a specific embodiment, patients suffering from or having previouslysuffered from Barrett disease are treated using the ECM device of theinvention.

In another specific embodiment, patients suffering from or hadpreviously suffered from esophageal cancer are treated using the ECMdevice of the invention.

EXAMPLES Overview of Experimental Design

Sixteen adult healthy mongrel dogs weighing between 17 and 24 kg weredivided into 2 groups. Each dog was subjected to a complete transectionof the esophagus and anastomosed in an end-to-end fashion. Both groupswere reinforced with an ECM scaffold that was telescoped inside theanastomosis. The measured endpoints included esophageal function andmorphological characteristics.

Group 1: Cervical Esophageal Anastomosis

The dogs in group 1 (n=6) were subjected to a complete transection ofthe esophagus in the mid-cervical region with surgical resection of 1.5cm of the full circumferential endomucosa from both ends. The endomucosawas defined as the epithelium, basal lamina (basement membrane), lamina,plus the tunica submucosa, leaving only the muscularis externa. Atubularized form of the urinary bladder matrix (UBM) was anastomosed tothe ends of the remaining endomucosa, and the ends of the overlyingmuscularis externa were anastomosed (see, e.g., FIGS. 3A-3D). A controldog underwent the same surgical procedure without device implantation.

Group 2: Gastroesophageal Junction Anastomosis

The dogs in group 2 (n=6) were subjected to a complete section of thegastroesophageal (GE) junction to assess the remodeling of the ECM in anacidic environment; the environment of an anastomosis created during agastric pull-up procedure. The endomucosa on the esophageal side of thetransection was resected and a funnel shaped UBM scaffold anastomosedproximally to the free end of the endomucosa and sutured distallythrough the stomach wall (see, e.g., FIGS. 4A-4C). One dog was subjectedto a complete transection of the GE junction and repaired withoutendomucosal resection or ECM scaffold implantation. Two dogs wheresubjected to transaction of the GE junction followed by endomucosalresection without ECM scaffold placement.

The dogs were survived until stricture formed that prevented swallowingor elective euthanasia was performed at prescribed time points rangingfrom 30 to 180 days.

ECM Device Preparation

Porcine urinary bladders were harvested from market weight(approximately 110-130 kg) pigs (Whiteshire-Hamroc, Ind.). Residualexternal connective tissues, including adipose tissue, was trimmed andall residual urine removed by repeated washes with tap water. Theurothelial layer was removed by soaking of the material in 1 N saline.The tunica serosa, tunica muscularis externa, the tunica submucosa, andmost of the muscularis mucosa were mechanically delaminated from theremaining bladder tissue. The remaining basement membrane of the tunicamucosa and the subjacent tunica propria, collectively termed urinarybladder matrix (UBM), were then isolated and disinfected anddecellularized by immersion in 0.1% (v/v) peracetic acid (σ), 4% (v/v)ethanol, and 96% (v/v) sterile water for 2 h. The UBM-ECM material wasthen washed twice for 15 min with PBS (pH=7.4) and twice for 15 min withdeionized water. Multilayer tubes were created by wrapping hydratedsheets of UBM around a 22 mm perforated tube/mandrel that was coveredwith umbilical tape for a total of four complete revolutions (i.e., afour layer tube). To fabricate the GE junction device, a custom mold wasconstructed in the shape of a funnel, with a perforated straight tube(25 mm diameter) connected to a bowl (80 mm diameter). Hydrated sheetsof UBM were formed around the mold until a total of four-6 layers werepresent. Prior to placing the ECM on the mold, the tube was wrapped withumbilical tape and the bowl was wrapped with cheese cloth to facilitateremoval of the UBM. The constructs were finally placed into a plasticpouch and attached to a vacuum pump (Leybold, Export, Pa., Model D4B)with a condensate trap inline. The constructs were subjected to a vacuumof 28 to 29 in Hg for 10 to 12 h to remove the water and form a tightlycoupled multilayer laminate. Each device was then removed from themandrel and terminally sterilized with ethylene oxide.

Surgical Procedures

Each animal was anesthetized by intravenous administration of sodiumthiopental and a surgical plane of anesthesia was maintained byintubation and inhalation of Isofluorane in oxygen. The surgical areawas shaved and prepared with standard draping for aseptic surgery.

Group 1

In this group of dogs, a midline cervical incision was made, and tissuelayers dissected to isolate the esophagus. A complete transection of theesophagus was made and 1.5 cm of the endomucosa was resected from cutends of both the proximal and distal segments. A tubular ECM scaffoldwas telescoped within the remaining muscularis mucosa and sutured to theproximal mucosal end with two short running sutures of either Prolene5.0 or PDS 5.0 and to the distal end with 4 separate stitches equallyspaced about the circumference. Finally an end-to-end anastomosis of themuscularis mucosa was performed with separate stitches of PDS 3.0. Thecervical wound was closed by layers with Vicryl 3.0. The same procedurewas repeated for the control dog without implanting the scaffold.

Group 2

In this group of dogs, a midabdominal incision was made, the triangularligament of the liver was sectioned, and the diaphragm hiatus wasdissected to expose the GE junction. A complete transverse section ofthe GE junction was made and 1.5 cm of the esophageal endomucosa and a 5mm ring of gastric mucosa were resected. The funnel shaped ECM devicewas telescoped within the structures. The tubular segment of the devicewas anastomosed to the esophageal mucosa with 2 short running sutures ofPDS 5.0 and the flared portion fixed to the gastric wall with 4 separatestitches of PDS 4.0. The gastroesophageal end-to-end anastomosis wascompleted by restoring the muscularis externa with separate 3.0 PDSsutures. The abdominal cavity was closed by layers with Vicryl 2.0,Prolene 1.0, and PDS 3.0, respectively. A chest tube was placed on theleft side since the pleural cavity was opened during hiatus dissection.The same procedure was repeated for control dogs with the modificationsdescribed in the experimental design overview.

Post Surgical Care

The dogs were recovered from anesthesia, extubated and monitored in therecovery room until they were resting comfortably in sternal position.The dogs were kept in a cage overnight and returned to their larger runhousing on postoperative day one. The dogs were given prophylacticantibiotics consisting of Cephalothin/Cephalexin (35 mg/kg PO), bid×7 to9 days. After surgery the dogs received Acepromazine (0.1 mg/kg IV) andButorphanol (0.05 mg/kg IV), followed by Buprenorphine (0.01-0.02 mg/kg,SC or IM q 12 h) thereafter for analgesia as needed. The dogs in group 2(including controls) were given 20 mg of Omeprazole daily. Dogs were fedfrom an elevated/raised platform. The dog's daily nutrition wascalculated and divided into 2 to 3 feedings per day. Gruel/soft food wasprovided for 1 week postsurgery. The animals were reintroduced to solidfood over a 2 week period with oral intake starting 36 hour aftersurgery. The dogs were weighed weekly and housed in a run measuringapproximately 10×14 ft to allow freedom to ambulate. Endoscopicexaminations were completed at approximately monthly intervals toevaluate esophageal structure and function.

Morphological Examination

Immediately after euthanasia, the cervical esophagus was harvested. Theharvested tissue included the scaffold placement site plus nativeesophageal and/or gastric tissue both proximal and distal to the graftsite. The excised sample was opened by making a longitudinal incision inthe distal to proximal direction. The exposed mucosal surface wasexamined and the tissue was then immersed in 10% neutral bufferedformalin, trimmed, sectioned, and stained with both Hematoxylin andEosin and Masson's Trichrome stains. The areas examined included thenative tissue, the proximal and distal anastomoses of the scaffold, andthe mid-scaffold region where the native end-to-end anastomosis wasmounted.

The clinical control showed healing of the anastomosis site with scartissue formation. There was an invagination of the mucosa and a thinband of fibrous connective tissue (scar tissue) extending fromimmediately beneath the mucosal epithelium to the abluminal portions ofthe tunica muscularis.

The experimental controls showed scarring at the anastomosis site. Therewas a slight invagination of the mucosal epithelial cells and a denseband of connective tissue extending from immediately beneath the mucosalepithelial cells to the outermost layer of the tunica muscularisexterna.

All dogs in which the ECM biologic scaffold was placed showed an intact,confluent layer of mucosal epithelium with reconstitution of thesubmucosal layer and the muscularis externa layer. There were thin,scattered bands of fibrous connective tissue intermixed with islands ofmuscle in the region of the muscularis externa. No such new muscletissue was seen in the dogs in which no ECM scaffold was placed.

Thus, the ECM scaffold provided constructive remodeling of all layers ofthe esophagus and gastroesophageal junction and minimized or preventedscar tissue formation at this site.

Having described this invention, it will be understood to those ofordinary skill in the art that the same can be performed within a wideand equivalent range of conditions, formulations and other parameterswithout affecting the scope of the invention or any embodiment thereof.

We claim:
 1. A method of reinforcing a gastroesophageal anastomotic sitein a patient comprising implanting a device comprising one or morelayers of extracellular matrix tissue and comprising: a) a tubularesophageal portion having essentially a constant diameter; and b) atubular gastric portion attached to the esophageal portion at a junctionhaving a diameter that increases from the junction to a distal tip ofthe gastric portion at an anastomosis between a portion of the patient'sesophagus and stomach.
 2. The method of claim 1, wherein the device isattached externally to the patient's remaining esophagus and stomach. 3.The method of claim 1, wherein the device is attached internally to thepatient's remaining esophagus and stomach.
 4. The method of claim 3, inwhich endomucosa is removed from the patient's esophagus and/or stomachwhere the device is implanted.
 5. The method of claim 1, wherein thediameter of the gastric portion of the device increases in anessentially uniform manner from the junction to the distal tip of thegastric portion.
 6. The method of claim 1, wherein the gastric portionof the device is modeled to conform with a portion of a patient'sstomach.
 7. The method of claim 6, wherein the gastric portion of thedevice is modeled to conform with a cardiac region of a stomach adjacentto a cardiac opening of the stomach.
 8. The method of claim 1, whereina) the esophageal portion of the device has a length of between 1 to 30cm and a diameter of between 0.5 to 5 cm; and b) the gastric portion ofthe device has a length of between 1 to 8 cm and the distal tip of thegastric portion has a diameter of between 1-12 cm.
 9. The method ofclaim 8, wherein a) the esophageal portion of the device has a length ofabout 3 cm and a diameter of about 2.3 cm; and b) the gastric portion ofthe device has a length of about 3-4 cm and a diameter of the distal tipof about 7 cm.
 10. The method of claim 1, wherein the extracellularmatrix tissue is isolated from urinary bladder tissue.
 11. The method ofclaim 1, wherein the extracellular matrix tissue is isolated fromintestinal submucosa.
 12. The method of claim 11, wherein theextracellular matrix tissue is isolated from small intestinal submucosa.13. The method of claim 1, wherein the extracellular matrix tissue isisolated from dermis of skin.
 14. The method of claim 1, wherein theextracellular matrix tissue is isolated from the esophagus.
 15. Themethod of claim 1, wherein the device comprises 2-10 layers ofextracellular matrix tissue.
 16. The method of claim 1, wherein thedevice is seeded with cells.
 17. The method of claim 16, wherein thecells are human.
 18. The method of claim 17, wherein the cells areobtained from a patient into whom the device is to be implanted.
 19. Amethod of joining a resected gastroesophageal junction in a patientcomprising attaching a device comprising one or more layers ofextracellular matrix tissue and comprising: a) a tubular esophagealportion having essentially a constant diameter; and b) a conical gastricportion attached to the esophageal portion at a junction having adiameter that increases from the junction to a distal tip of the gastricportion to at least a portion of the patient's esophagus and at least aportion of the patient's gastric wall, wherein the tubular portion isattached to at least a portion of the patient's esophagus and theconical portion is attached to at least a portion of the patient'sgastric wall.